Baseball, I sometimes think, really is a sort of civic religion — because even under close observation, most of what matters in an average game must be taken on faith.

The next time you have really good seats at the ballpark, take a radio with you and listen to the broadcast while paying careful attention to what happens on the field. You’ll quickly notice that one has no relation whatever to the other. Announcers routinely claim that inside pitches were on the outer half of the plate, or that fastballs were changeups, or that terrible throws from the outfield were on a line. Fans by the millions will swear that Derek Jeter is an exceptionally alert defensive player, yet he frequently doesn’t bother to adjust his positioning between pitches and also has a bizarre habit of pounding his glove and staring off into the stands while Jorge Posada is laying down the signs.

What happens on the field doesn’t really matter, because it’s impossible to take it all in. Sitting in an announcing booth, it’s often impossible to tell if a pitch was high or low; sitting in the stands, it’s impossible to keep track of all the subtle shifts and movements of eight fielders while also keeping an eye on runners and the batter, especially while a vendor is crossing your sight line. In the end, because of the speed of the game and the difficulty of taking it in whole, most people are guessing about what’s happening right in front of them.

Inevitably, this gives rise to a priesthood of people who can interpret the mystery. You may think you just saw Nuke LaLoosh throw a ball that moved from west to east across the plate on a flat line, but your chipper announcer is ready to praise his curveball, and so a curveball has been thrown. You may think you just saw the shortstop standing completely still for an entire at-bat before watching a ball skate off four feet to his left, but the season ticket holder in the seat next to you is ready to praise his superior positioning at exhausting length.

This sort of thing is enough to make one throw up his or her hands in disgust at the sum of all baseball knowledge — it is, after all, just a game in which people throw the ball, hit the ball, and catch the ball, and anything more complicated than that is just a way to give yourself a headache. What’s the point of knowing anything about baseball if none of it means anything? One person can say that a hitter’s swing is long, and another can say his swing is short, and these will generally be treated not as statements that can be either proved or disproved, but as acts of interpretation, valid in direct proportion to the authority of the person making the claim.

The shame of all this isn’t that it turns baseball commentary and opinion into a sort of incomprehensible blur of smarmy jargon and mysterious assertions, but that it leaves people not trusting their own eyes.

Tonight, for instance, the Mets may very well have a no-hitter tossed at them by a brilliant pitcher who’s about as good as Sandy Koufax was in his prime. Any team capable of striking out 10 times against Chien-Ming Wang, who strikes out fewer batters than anyone else in baseball, is in danger of being outright humiliated by Johan Santana. And how will Santana do this? He’ll throw a pillowy changeup that floats up to the plate in a straight line and leaves the batter swinging too soon, and he’ll throw one that will roll sharply down and leaves the batter swinging over the top of it. More important, he’ll keep his arm moving at the same speed no matter what pitch he’s throwing, he’ll throw pitches in three different registers, and he’ll throw strikes, especially first pitch strikes. This is what he always does.

Watch Santana closely tonight. All of this is demonstrably true of him in a way it isn’t true of, say, Jorge Sosa, who will be pitching for the Mets. But the explanation has no power to persuade, because it’s the sort of thing that’s said about every successful pitcher. Anyone who’s able to win a few games in a row in the major leagues will be praised by someone, and often a lot of someones, for his good arm action and for his ability to change pitches and throw strikes, perhaps even quality strikes, and so on. This isn’t unusual.

Obscurantist rhetoric, though, can’t obscure just how special Santana is, and how different he is from someone such as Sosa, which is why baseball isn’t, in the end, a civic religion. You don’t have to take anything on faith; you just have to pay attention. Everything a good pitcher is supposed to be will be there for anyone to see on the mound at Shea tonight. Don’t take anyone’s word for it; see it for yourself.

tmarchman@nysun.com